Matrix/Riot has a lot of anti-abuse stuff fwiw - https://matrix.org/docs/guides/moderation https://matrix.org/docs/guides/moderation has more details, and we're

Matrix/Riot has a lot of anti-abuse stuff fwiw - https://matrix.org/docs/guides/moderation https://matrix.org/docs/guides/moderation has more details, and we're about to launch a shared blacklist feature in addition.